Sugar-evaporator



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. SUGAR'EVAPORATOR. No. 308,407; Patented Nov. 25, 1884.

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SUGAR BVAPORATOR.

No. 308,407. Patented Nov. 25, 1884.

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v SUGAR EVAPORATOR. Y No. 308,407. Patented .Nov. 25, 1884.

UNITED STATES ArENr rrrce;

I JAMES F. FERGUSON AND CHARLES :0. POST, OF BURLINGTON, VERMONT.

SUGAR-EVAPO RATO R.

SPECIFICATION forming part of Letters" Patent No. 308,407, dated November 25, 1884.

Application filed August 31, 1883. (No model.)

To all whom it may concern:-

Be it known that we, JAMES F. FERGUSON and CHARLES C. Posr, citizens of the United States, residing at the city of Burlington, in the county of Chittenden and State of 'Vermont, have invented certain new and useful Improvements in Sugar-Evaporators, of which the following is a specification, reference being had therein to the accompanying drawings.

Our invention relates to improvements in evaporators designed to reduce sap or other saccharine liquids to sirup orsugar; and the object of our improvements is to so arrange the construction of our apparatus that the sap or other saccharine liquid shall be so treated in the process of evaporation as to produce in the shortest time the largest and purest quality of sirup, and hence the greatest quantity of the best sugar, inasmuch as every portion of our pan is at all times under the entire con 'trol of the operator, so that the sap or saccharine liquid can be readily subjected .to whatever degree of heat is deemed advisable, and the causes which prevent the best results are either avoided or so managed as to have neath them, whereby the fiow of the sirup may be controlled at any desired point, and the degree of heat to which each section shall be subjected such as shall best conduce to the desired result. The remainder of the pan is dividedinto longitudinal sections having suitable hot-air fiues so arranged and connected together that a regular and continuous volume of sap or saccharine liquid enters the pan at the point of greatest heat, and thence passes into the first section, where the scum or fecal matter can be conveniently removed, and thence steadily fiows through the several longitudinal sections, where, by the arrangement of the hot-air fiues, it is subject to a rapid and continuous evaporation until, as it enters the transverse sections, it is either ready to be siruped off, or, by being still further subjected to a gradually-decreasing heat, regulated by dampers, it reaches the point where crystallization successfully takes place. By this construction the usual expense of building and permanently maintaining an extensive arch is greatly reduced, the entire heat utilized, and the amount of fuel required proportionately diminished. By means of a convenient arrangement of dampers and upper, and lower series of hot-air fiues beneath the longitudinal sections heat may be applied in such degree as maybe desired; or, as the process of evaporation'draws to a close the heat may be entirely cut off from, first, theseotional fiues; second, from the bottom of the pan;' and, last ly,-diverted to the chimney in another way, I

all of which will be more fully described here inafter. I attain these objects by the apparatus illustrated in the accompanying drawings, in which Figure 1 is aperspective view of the cvaporater-pan. Fig. 2'is a perspective view of the bottom of the same pan, looking toward its rear end. Fig. 3 is a perspective View of the same pan, looking toward the front end and showing the heating-fiues, sections, and

gates. Fig. 4 is a perspective View of the arch, fiues, and chimney. Fig. 5 is a cross-section of the arch onthe line a: 3 Fig. 6 is a perspective View of the gate and frame. Fig. 7 is a perspective view of the evaporator complete.

Similar letters refer to similar parts throughout the several views.

A represents the arch or fire-chamber, of rectangular shape and suitable construction, preferably from three to four feet in length.

B is the door opening into the same, and G the fire-grating. Near the top of the interior end of the arch A is a fiue,F, of the same width as the arch. It extends horizontally any length desired, and connects with the chimney or smoke-fine G. The upper portions of the fiue F at'each endare open to ICO form, when desired, a direct draft from the fire-chamber to the chimney, directly below the bottom of the pan. By this arrangement heat can be more easily retained in the lower,

I upper edge.

, tion.

portion of the flue, the openings being closed by the dampers H and I.

Below the flue F and leading from the firechamber to the chimney is a smoke pipe or pipes, J. Its opening into the former is regulated by the valve or damper j. The several valves or dampers are conveniently operated by handles at the side of the apparatus.

K is a rectangular evaporating-pan, made of metal, and of suificient size to cover the entire fire-chamber A and the flue F by which it is supported. The connection between the pan K and its supports is made air-tight by means of a metallic rim or strip, Ii, so arranged as to form a ledge around the pan, the space intervening between it and the lower edge of the pan being filled in with suitable packing material, so as to effectually prevent any chilling of the pan by the ingress of cold air beneath it, as well as the escape of any heat or flame which might scorch or burn the sides of the pan or the wooden guard around its The portion of the pan over the fire-chamber is divided transversely into two or more sections, M, according to the length of the arch, sufficient space being left over the rear end of the arch for the section N, which extends from one side of the pan to the outlet 1) of the longitudinal section 0, through which the sirup is admitted into the first of the transverse sections M. From the section N the pan is divided longitudinally by partitions 1? into three or moresections, Q, according to the width of the pan and the requirements for evapora- \Vithin each longitudinal section and about one inch above its bottom are one or more hot-air tubes or fiues, R, communicating with the fire-chamber through the heating.

chamber 0' within the section N and the flue of the chimney, thus forming a direct connection of the furnace with the chimney forthe passage of heat and smoke. If the sides of the pan are about ten inches in height, the tubes It are from three to five inches square. The opening between the bottom of the chamber 'r and the fire-chamber is closed by the slide or damper S. In the rear of the chi1n ney opposite the ends of the tubes It is an opening closed by the door T, to allow a swab to be passed into the tubes to clean them, as occasion may require, without removing the pan. At alternate ends of the partitions openings m are provided for the under and over flow of .the sap as it flows through the sections, the former being at the bottom of the partition and the latter at a suificient height above the tubes It to insure their being covered during the process of evaporation.

In order that the scum or fecal matter may be removed as far as possible in the early process of boiling the side section, Q, may be of greater width than the others, so that as the scum is naturally driven by the effect of the boiling to the cooler side of the section, which is the outside of the pan, it can be conveniently removed. To render this separation more effectual, a cloth strainer, U, with a metal tube or mouth-piece is removably attached to the overflow of this section, to retain whatever is thrown to the surface by ebullition, and escapes the skimming. As the boiling process proceeds and the sap flows into the siruping-ofi section M, a deposit known as silica is frequently formed. To separate this deposit, which isheavier than the sap, a pocket,

Y, with its-cock z, is attached to the bottom of one or more of the sections M, into which it opens for the purpose of collecting the deposit as it flows through the section. The degree of heat which is required for the siruping-off sections M is regulated by the slides or dampers 12 under each section. These are perforated or solid, as desired. Above these slides are openings to through the sides of the firechamber, which can be closed at will. They are designed to admit a current of cold airbeneath eachsection should it be desired to still further reduce their temperature. The sections discharge their contents into each other through the gates cl, located at the bottom of the partitions, which separate them at their alternate ends. As these gates require to be absolutely water-tight, so that the depth of the sap in any section may be varied at will, it is apparent that the slide ordinarily used for such purposes cannot be successfully-employed.

The gate as constructed by us and shown in Fig. 6 consists of a metallic frame, b, which is attached to the partition of any section through which an opening is desired, and is so arranged as to closely fit the vertical slide (1.

To the lower and side edges of this slide, which is made of wood, is attached a packing made of felt or other fibrous material, to prevent the passage of any sap around the slide when closed. An opening, 6, through the bottom of the frame I), and a corresponding opening, f, through the partition allows the sap to flow readily from one section to the other when the slide is raised. Each section can be emptied through cocks a.

In operation the entire pan is first covered with sap, and the cold sap is then supplied continuously to the pan at the section N, where, by reason of the central position of the section on the line of direct draft and the location within it of the heating-chamber r, it can be at once subjected to the most intense heat. Its flow is rendered regular and continuous by its passage through a suitable heat-current into the tubes It. The sap being thus subjected to the heat retained in the flue F, and that which passes from the chambers 1' through the tubes B, is soon raised to a boiling-point, and the process of evaporation rapidly proceeds, the sweetness of the sap continually increasing as it flows from section to section. The great extent of heatingsurface thus provided beneath and throughthe sap, greatly hastens the process of evaporation, and thus prevents injury to the sap by exposure to the air. By means of the watertight gates d the liquid is run in whatever quantity desired into the siruping-off sections M, from whenceit can be drawn according to the quality or weight desired, that drawn from the last section being ready for crystallization. As the process of evaporation draws to an end close the slide S,which excludes theheat from the tubes R, and prevents their burning when not covered by the sap. The heat is then diverted into the flue F by opening the damper I for the purpose of boiling the sap to its lowest extent, after which the dampers H and I are closed and the damper j Opened thereby diverting the entire heat from the bottom of the pan over the flue F into the chimney through the under flue, J. This avoids the necessity of removing the pan while the sirup is being siruped off or sugared off in the transverse sections M. By means of the slidedampers o the heat can be shut off from each siruping-off section M as soon as it is empty, thus avoiding injury from burning.

By the above-described construction the heat required to reduce the sap is gathered directly in a large reservoir beneath the pan, where it is completely absorbed and utilized, thus avoiding the necessity for an extensive fire-chamber, thereby greatly economizing, both in the expense of construction and the amount of fuel required. The arrangement of the heating-fines in each evaporating-seetion preserves all the advantages of 'deepboiling, and prevents undue precipitation of grit or silica until the liquid has reached the density of heavy sirup or for sugaring off, and then a pocket is provided for it. At the same time the entire work is performed without necessitating the inconvenient removal of pans.

\Ve are aware that evaporator-pans subdivided into transverse and longitudinal sec tions communicating by openings closed by dampers, the latter sections containing smokefiues, have heretofore been used.

WVe are also aware that a pocket for catching Letters Patenters III for controlling the heat therein, and

the heat and smoke diverting flue J, substantially as described.

2. The metallic rim or flange L, around the top of the furnace-wall, extending upwardly therefrom to receive and retain in position the evaporating-pan, and alsoa packing to render the joint between the two smoke, gas, and air tight, substantially as described.

:3. The pocket Y, arranged before the opening into and extending below the bottom of the sugaring-off pan, to separate and retain grit, dirt, and silica from the sirup, substantially as described.

4. In an evaporating-pan, a gate for regulating communication between adjacent sections, consisting of the frame 6 and slide (1, provided with aliquid-tightpacking, substantially as described.

In testimony whereof we do affix our signatures in presence of two witnesses.

JAMES F. FERGUSON; CHARLES 0. POST.

Witnesses:

JASPER A. Bousn, CHARLES E. ALLEN. 

